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Apart from the Nest Thermostat‘s scheduling features and voice commands, its compact design and neutral tones were the perfect fit for my aesthetics.
My fog-colored Nest thermostat sits beautifully on the plain white wall.
I have had a few issues with my Nest Thermostat, like the time it wouldn’t charge, or the time I got a delayed message.
Thankfully, a great feature about Nest is that it gives you a specific error code whenever something’s wrong.
All you need to figure out is how to troubleshoot that error instead of having to check your wiring, your screen, and inspecting every little detail of your thermostat.
Recently, I got an error message that said, “E195 – No power to R detected”.
I appreciated this, as I now instantly knew where the problem was. But that did not make fixing it any easier.
I had to go through so many different articles and videos online before finding a proper solution.
So, I put together this comprehensive guide on how to trouble this issue.
The R-wire is responsible for powering your entire HVAC system. Therefore, your heating and cooling system will stop working or might even be damaged if there is something wrong with your R-wire.
When there is no power to the R-wire on your Nest thermostat, start by checking the wire itself.
You should also make sure your drain pan isn’t clogged and that your float switch hasn’t been tripped.
Check the System Power
The first method is checking if the power to the system is switched on. The switch is usually in your breaker box or fuse box.
There might be a single switch or two switches for heating and cooling.
Make sure both of them are turned on. If the power is on, check your thermostat to see if it is working.
Check your R-wire
The next step is checking your R-wire to see it’s frayed. To do this, you have to turn off the power at the breaker.
Now, remove the R-wire and straighten it. Finally, insert the wire back to the R connector.
If the button stays pressed down even after you let go, the issue should be fixed.
Turn the power back on and check if the error message has disappeared.
Check Your Thermostat Wiring
Pull off the thermostat from your wall and check if all the wires are inserted correctly. Here’s a checklist that you can follow.
If you’ve installed your Nest Thermostat without a C-Wire, this should be a lot easier.
- Check if all wires are inserted fully into the connector.
- Every wire should have 6 mm of exposed wire.
- Check if every wire is connected correctly to the system board.
Check if your float switch was tripped
A float switch is a safety device that prevents damage to your equipment. When you run your air conditioner, condensation begins to gather.
This should not go above a particular level. If it does, your thermostat will get defective soon.
The float switch will trip off when there is a condensate overflow. This will stop your air conditioner from working.
Although it is irritating to come home and see that your home is not at the temperature that you want it to be, this is much better than your A/C continuing the humidification process.
You can turn it back on after removing any clog that you find.
Check Your Condensate Drain Line
Float switches will let you know when there is a clog. But, they are designed to be self-resetting. So, your thermostat might be back on before you know it.
Instead of being optimistic about your thermostat’s working, you should check if your air conditioning is draining properly.
For instance, if you see that your thermostat screen is going blank from time to time or that the error message is being displayed repeatedly, they are hints that something is wrong.
If you choose to ignore it, you might wake up to leaks soon. Your drain system is a warm and dark place for bacteria to thrive.
The slime can build up in time and clog the drain line completely. This can not only damage your thermostat or air conditioner but your ceiling too.
Your HVAC system produces around 5 gallons of water every day. So, not getting rid of it can have disastrous effects.
If you notice that it isn’t draining properly and you find it hard to restore the flow, you should consider calling an HVAC technician.
Contact Support
If the troubleshooting methods discussed above did not help with your issue, you need to contact Nest support.
The team will get back to you within 24 hours.
Final Thoughts Regarding Getting Power to R Wire
Sometimes, the issue lies with the Nest app. In that case, a factory reset might help. However, consider this as a last resort because you’ll have to reset your schedules.
If you’ve forgotten your PIN, then there’s no need to worry. Here’s a comprehensive guide on how to Reset your Nest Thermostat without PIN.
Also, please note that you always need to turn off the power to your HVAC system before checking your thermostat’s wiring.
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- Nest VS Honeywell: Best Smart Thermostat For You [2021]
Frequently Asked Questions
What is the R wire on a thermostat?
The R wire on a thermostat is responsible for powering your heating and cooling systems.
What if there is no C wire for the thermostat?
You can use the existing G wire as a C-wire. Another solution is to use a C wire adaptor if there isn’t a C wire for the thermostat.
What happens if you wire a thermostat wrong?
There are several consequences to improper wiring, which include electric shocks and damaging the thermostat.
Can I use the G wire for the C-wire?
Yes, you may use the G wire for the C-wire in certain cases. For instance, if you don’t have any other equipment like humidifiers or purifiers attached to the fan or the thermostat is used only for cooling and not for heating.
